Use of (per) fluoropolyether compounds as additives in formulations

ABSTRACT

Use of mono- and bifunctional (per)fluoropolyether compounds as additives in formulations for the wood treatment, said (p-er)fluoropolyether compounds having the structures:  
     R f —O—CFY—L—W (C)  
     W—L—YFC—O—R f —O—CFY—L—W (D)  
     wherein:  
     L is an organic group selected from —CH 2 —(OCH 2 CH 2 ) n —, —CO—NR′—, with R′═H or C 1 -C 4  alkyl group; n═0-8; Y═F, CF 3 ; W is selected from C 1 -C 50  alkyl groups, optionally containing one or more ether O, C 6 -C 50  aryl groups, C 7 -C 50  alkyl-aryl or aryl-alkyl groups;  
     Rf is a (per)fluoropolyether radical.

[0001] The present invention relates to the use of additives for the protective treatment of wood materials to confer improved oil- and hydro-repellence properties.

[0002] Specifically, the invention relates to the addition of additives to the formulations usually utilized for the wood treatment, such as for example impregnating, antivegetative, insecticidal formulations, etc. Said additives are effectively used at very low surface concentrations, avoiding to modify the surface aspect of the treated wood material.

[0003] Compounds able to give wood hydro-repellence properties are known in the prior art. U.S. Pat. No. 5,141,983 which describes polyurethane-acrylic copolymers dispersed in water can for example be mentioned. The drawback of these products consists in that they are not able to confer suitable oil-repellence properties.

[0004] Other compounds, for example functionalized amino-organo hydrogenated siliconates are described in U.S. Pat. No. 5,178,668. Also for these products, there is the drawback that they are unable to confer suitable oil-repellence properties.

[0005] In U.S. Pat. No. 5,855,817 compounds having more than one hydroxyl function in combination with quaternary ammonium salts to confer hydro-repellence to wood, are described. Also in this case the oil-repellence properties are not high.

[0006] There are also aqueous formulations based on siliconates, polyurethanes and silicates, described in U.S. Pat. No. 5,356,716. Also in this case no mention is made to possible conferred oil-repellence properties.

[0007] Hydrocarbon solvent-based formulations comprising mixtures of fluoropolymers, hydrogenated silanes and silicones are described in U.S. PAT. NO. 5,593,483. Also in this case no mention is made to possible conferred oil-repellence properties.

[0008] In U.S. Pat. No. 5,691,000 specific perfluoropolyether phosphor monoester compounds able to give hydro- and oil-repellence to wood are described. The solvents used for the dissolution of these compounds are CFC-113 or alcohol/water mixtures. In this patent also other perfluoropolyether compounds having different functionalities are exemplified. The Examples show that these latter derivatives have lower hydro- and oil-repellence properties in comparison with the perfluoropolyether phosphor monoesters. In particular, the hydro-repellence values of phosphor monoesters when applied on wood are unsatisfactory. In fact, the Applicant has noticed that the oil- and hydro-repellence test is not sufficiently discriminating to identify the real protection degree given to wood. For this reason, these products have found a poor commercial application for the protective wood treatment. In this patent no mention is made to the use as additives of said products in the formulations used for wood.

[0009] The technical problem that the present invention intends to solve is that to find additives showing the following property combination:

[0010] improved hydro-repellence properties;

[0011] improved oil-repellence properties;

[0012] absence of any change of the wood natural aspect;

[0013] substantial maintenance of the properties conferred by impregnating, antivegetative, insecticidal, etc., formulations also after additive addition;

[0014] good compatibility of the additive with impregnating, anti-vegetative, insecticidal, etc. formulations so as to have substantially uniform oil- and hydro-repellence properties on the surface of the treated wood;

[0015] improvement of the wetting capacities of the above mentioned formulations for wood;

[0016] improved friction coefficient, i.e. decrease of the friction coefficient values of the wood surface which implies a wear limitation.

[0017] The need was therefore felt to have available additives for formulations used in the wood treatment, able to give the combination of the above mentioned properties.

[0018] An object of the invention are therefore mono- and bifunctional (per)fluoropolyether compounds and their use as additives in formulations for the wood treatment, excluding the formulations based on paraffin waxes dissolved in hydrocarbon solvents, said perf luoropolyether compounds having the following structures:

[0019] R_(f)—CFY—L—W (C)

[0020] W—L—YFC—O—R_(f)—CFY—L—W (D)

[0021] wherein:

[0022] L is an organic group selected from —CH₂—(OCH₂CH₂)_(n)—,

[0023] —CO—NR′—, with R′═H or C₁-C₄ alkyl group;

[0024] n═0−8, preferably 1−3;

[0025] Y═F, CF₃;

[0026] W is selected from C₁-C₅₀ alkyl groups, preferably C₈-C₂₅, optionally containing one or more ether O, C₆-C₅₀ aryl groups, C₇-C₅₀ alkyl-aryl or aryl-alkyl groups; Rf has a number average molecular weight in the range 350-8,000, preferably 500-3,000 and it comprises repeating units having at least one of the following structures, statistically placed along the chain: (CFXO) , (CF₂CF₂O), (CF₂CF₂CF₂O), (CF₂CF₂CF₂CF₂O), (CR₄R₅,CF₂CF₂O) , (CF(CF₃)CF₂O), (CF₂CF (CF₃)O),

[0027] wherein

[0028] X═F, CF₃;

[0029] R₄ and R₅, equal to or different from each other, are selected from H, Cl, or perfluoroalkyl from 1 to 4 carbon atoms.

[0030] In particular Rf can have one of the following structures:

[0031] 1) —(CF₂O) (CF₂CF₂O)_(b′)—with a′/b′ in the range 0.5-2, extremes included, a′ and b′ being integers such as to give the above mentioned molecular weight;

[0032] 2) —(C₃F₆O)_(r)—(C₂F₄O)_(b)—(CFXO)_(t)—with r/b═0.5-2.0; (r+b)/t is in the range 10-30, b, r and t being integers such as to give the above mentioned molecular weight, X has the above mentioned meaning;

[0033] 3) —(C₃F₆O)_(r′)—(CFXO)_(t′)—t′ can be O; when t′ is different from O then r′/t′═10-30, r′ and t′ being integers such as to give the above mentioned molecular weight; X has the above indicated meaning;

[0034] 4) —(OCF₂CF(CF₃) )_(z)—OCF₂(R′f)_(y)—CF₂O—(CF(CF₃)CF₂O)_(z)—wherein z is an integer such that the molecular weight is the above mentioned one; y is an integer between 0 and 1 and R′f is a fluoroalkylene group having for example 1-4 carbon atoms;

[0035] 5) —(OCF₂CF₂CR₄R₅)_(q)—OCF₂(R═f)_(y)—CF₂O—(CR₄R₅CF₂CF₂O)_(s)—

[0036] wherein: q and s are integers such that the molecular weight is the above mentioned one; R₄, R₅, R′f, y have the above mentioned meaning;

[0037] 6) —(C₃F₆O)_(r′″)(CFXO)_(t′″)—OCF₂(R′f)_(y)—CF₂O(CF(CF₃)CF₂O)_(x″′(CFXO)) _(t′″)—wherein r′″/t′″═10-30, r′″ and t′″ being integers such as to give the above mentioned molecular weight; R′f and y having the above mentioned meaning.

[0038] In the above indicated formulas:

[0039] —(C₃F₆O)—can represent units of formula

[0040] —(CF(CF₃)CF₂O)—and/or —(CF₂—CF(CF₃)O)—

[0041] In the structure (C) wherein Rf is monofunctional, the other end group is of the T—O—type, wherein T is a (per) fluoroalkyl group selected from: —CF₃, —CF₅, —C₃F₇, —CF₂Cl, —C₂F₄Cl, —C₃F₆Cl; optionally one or two F atoms, preferably one, can be replaced by H.

[0042] The mentioned fluoropolyethers are obtainable by the well known processes in the prior art, see for example the followwing patents herein incorporated by reference: U.S. Pat. Nos. 3,665,041, 2,242,218, 3,715,378, and EP 239,123. The functionalized fluoropolyethers are for example obtained according to EP 148482, U.S. Pat. No. 3,810,874.

[0043] The compounds of structure (C) are obtained by reacting a monofunctional perfluoropolyether ester derivative with an alkylamine. The alkylamine, generally under waxy form, is melted at a temperature in the range 40°-60° C. The perfluoropolyether ester derivative is dropped in the amine in an equimolar amount under stirring and maintaining the reactor at the desired temperature. At the end of the addition the alcohol which has formed from the condensation reaction is evaporated.

[0044] The compounds of structure (D) are obtained by reacting a bifunctional perfluoropolyether ester derivative with an alkylamine. The alkylamine, generally under waxy form, is melted at a temperature in the range 40°-60° C. The bifunctional perfluoropolyether ester derivative is dropped in the amine in molar amount 0.5 with respect to the amine under stirring and maintaining the reactor at the desired temperature. At the end of the addition the alcohol which has formed from the condensation reaction is evaporated.

[0045] The preferred compounds of the invention have structure (D) wherein L is —CO—NR′—, with R′═H; W is a C₈-C₂₅ alkyl group; Rf has structure 1).

[0046] Mixtures of the above mentioned compounds (C) and (D) can also be used.

[0047] The Applicant has surprisingly found that by using the above defined (per) fluoropolyether derivatives as additives of formulations for the wood treatment, the combination of the above mentioned properties is obtained. This result is unexpected since the same compounds of structure (C) and (D) not used as additives in formulations for wood, but used alone as treating agents are not able to confer high oil- and hydro-repellence properties, the concentrations being the same. The Applicant has found that in order to obtain comparable hydro- and oil repellence values on wood, when the components of the invention are used alone dispersed in solvents, it is necessary to carry out repeated treatments (at least 3). From the industrial point of view this represents a remarkable application drawback besides higher costs.

[0048] The formulations for wood to which the additives of the invention are added are those known for the wood treatment: impregnating, antivegetative, insecticidal, anti-mould formulations, paints, etc. can be mentioned. Preferably said formulations for wood are based on solvents, such as for example ketones, alcohols, glycols, hydrocarbons.

[0049] The impregnating formulations prevailingly comprise as main components natural oils, acrylic and polyurethane polymers. The anti-vegetative formulations prevailingly comprise as main components limonene, alkyd resins and fluorinated acrylic polymers. The insecticidal formulations prevailingly comprise as main components dichlofluoranid, permethrin, linseed oil and dibutylphthalace.

[0050] The additives of the invention are added to the formulations in concentrations in the range 0.01-10% by weight, preferably 0.1-5% by weight with respect to the formulation weight. The application of the formulation can be carried out by brushing, spraying, etc. Optionally, if required by the industrial application process, after the treatment a thermal treatment can be carried out for a quicker removal of the solvent.

[0051] The present invention will be better illustrated by the following Examples, which have a merely indicative but not limitative purpose of the scope of the invention itself.

EXAMPLES

[0052] Evaluation of the oil-repellence properties

[0053] The oil-repellence properties conferred to a wood substratum by the perfluoropolyether (PFPE) products of the invention have been evaluated, after treatment of the wood specimen with a solution at different concentrations by weight of product, following the procedure reported below:

[0054] 10 μl of vaseline oil are deposited on the treated surface by a syringe;

[0055] the area increase of the deposited drop at subsequent times (5,10,15,20 minutes) is determined.

[0056] A greater diffusion of the drops deposited on the treated wood surface and therefore a higher area of the drop show a lower repellent power of the treatment and therefore lower oil-repellence conferred.

[0057] Evaluation of the hydro-repellence properties

[0058] The hydro-repellence properties conferred to a wood substratum by the perf luoropolyether products of the invention have been evaluated as follows: after treatment of the wood specimen with a solution at different concentrations by weight of product, the hydro-repellence of the treated wood is evaluated by depositing 5 μl of a mixture of water/isopropanol on the treated surface. The area of the deposited drops water/isopropanol (at two ratios by weight water/isopropanol equal to 60:40 and 30:70) is measured after one minute from the deposition. A higher drop area on the treated surface shows a lower repellent power of the treatment and therefore lower hydro-repellence conferred.

EXAMPLE 1

[0059] A monofunctional perfluoropolyether compound (PFPE) having formula:

Cl(C₃F₆O)_(n)CF₂—C(O)—NH—C₁₈H₃₇  (I)

[0060] is used, wherein n═2-5

[0061] To a commercial anti-vegetative formulation LINFO® (GEAL) containing limonene, alkyd resins and fluorinated acrylic polymers, the compound of formula (I) is additived at a concentration equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Hemlock wood specimen. At the end of the treatment, before carrying out the oil-repellence test, the wood specimen has been placed in a stove at T═60° C. for 2 hours in order to facilitate the solvent evaporation present in the anti-vegetative formulation.

[0062] The anti-vegetative formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already starting from only one coat application. The oil-repellence test values evaluated on Hemlock wood treated with different concentrations of the perf luoropolyether additive are reported in Table 1. Such data are compared with those of the not additived anti-vegetative formulation (first column) always applied in one single coat. TABLE 1 PFPE concentrations of formula (I) — 1% by wt. 5% by wt. 10% by wt. Drop area 60.8 mm² 55 37.9 35.6 after 5 min. Drop area 82.2 mm² 67.3 44.5 39.8 after 10 min. Drop area 97.6 mm² 73.8 48.8 44.5 after 15 min. Drop area 99.4 mm² 75.2 50.4 48 after 20 min.

[0063] The same wood specimen have furthermore been subjected to hydro-repellence tests by depositing drops of water/isopropanol mixtures having a ratio by weight 60/40 and 30/70 and evaluating the drop area after one minute. The obtained results, compared with those resulting from the application of the anti-vegetative not additived formulation (first column) always applied in one single coat, are reported in Table 2. TABLE 2 PFPE concentrations of formula (I) — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40   20 mm² 9.7 8.0 7.5 Drop area H₂O/IPA 30/70 56.3 mm² 43.2 15.4 15.0 Drop area

EXAMPLE 2

[0064] A bifunctional perfluoropolyether (PFPE) compound having formula:

H₃₇C₁₈NH—C(O)—CF₂O(CF₂CF₂O)_(n)(CF₂O)_(m)CF₂—C(O)—NH—C₁₈H₃₇  (II)

[0065] is used.

[0066] The compound of formula (II) is dissolved in methylethylketone forming a solution at 50% by weight. Said solution is additived to the commercial anti-vegetative formulation LINFO® (GEAL) obtaining a final concentration of compound (II) equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Hemlock wood specimen.

[0067] The anti-vegetative formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 3, the hydro-repellence test values in Table 4, compared with those obtained with the not additived anti-vegetative formulation (first column) always applied in one single coat. TABLE 3 Bifunctional PFPE concentrations of formula (II) — 1% by wt. 5% by wt. 10% by wt. Drop area 60.8 mm² 17.8 13.6 13.6 after 5 min. Drop area 82.2 mm² 17.5 14 13.6 after 10 min. Drop area 97.6 mm² 18.9 14.4 13.6 after 15 min. Drop area 99.4 mm² 19.4 14.8 13.6 after 20 min.

[0068] TABLE 4 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40   20 mm² 7.4 6.7 6.7 Drop area H₂O/IPA 30/70 56.3 mm² 10.0 8.1 7.7 Drop area

EXAMPLE 3

[0069] To a commercial impregnating formulation XYLOVALCERA® (VELECA) containing natural oils, acrylic and polyurethane polymers, the perfluoropolyether compound of formula (I) is additived at a concentration equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Hemlock wood specimen.

[0070] The impregnating formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 5, the hydro-repellence test values in Table 6, compared with those obtained with the not additived impregnating formulation (first column) always applied in one single coat. TABLE 5 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 200 mm² 91.2 36.2 32.2 after 5 min. Drop area 200 mm² 134.6 34.1 35.2 after 10 min. Drop area 200 mm² 150 60 38.6 after 15 min. Drop area 200 mm² 180 64 47.2 after 20 min.

[0071] TABLE 6 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 100 mm² 9.8 8.9 10.4 Drop area H₂O/IPA 30/70 100 mm² 16 13.6 13.8 Drop area

EXAMPLE 4

[0072] The perfluoropolyether compound of formula (II) is dissolved in methylethylketone forming a solution at 50% by weight. Said solution is additived to the commercial impregnating formulation XYLOVALCERA°0 (VELECA) obtaining a final concentration of compound (II) equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Hemlock wood specimen.

[0073] The impregnating formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 7, the hydro-repellence test values in Table 8, compared with those obtained with the not additived impregnating formulation (first column) always applied in one single coat. TABLE 7 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 200 mm² 19.1 15.8 13.1 after 5 min. Drop area 200 mm² 19.1 16 13.8 after 10 min. Drop area 200 mm² 20.6 16 13.9 after 15 min. Drop area 200 mm² 21.6 16.5 14 after 20 min.

[0074] TABLE 8 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 100 mm² 8.6 8.4 7.4 Drop area H₂O/IPA 30/70 100 mm² 11.4 11.3 10.9 Drop area

EXAMPLE 5

[0075] To a commercial insecticidal formulation XYLAMON® (SOLVAY) containing dichlofluoanide, pernetrine, linseed oil and dibutylphtalate, the perfluoropolyether compound of formula (I) is additived at a concentration equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Hemlock wood specimen.

[0076] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 9, the hydro-repellence test values in Table 10, compared with those obtained with the not additived insecticidal formulation (first column) always applied in one single coat. TABLE 9 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area   51 mm² 48.8 37 36 after 5 min. Drop area   61 mm² 55.8 42.5 39 after 10 min. Drop area 73.7 mm² 56.0 52.7 41 after 15 min. Drop area 84.8 mm² 58.9 59 58.5 after 20 min.

[0077] TABLE 10 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 22.2 mm² 9.2 7.9 7.3 Drop area H₂O/IPA 30/70 43.8 mm² 18.7 16.3 13.3 Drop area

EXAMPLE 6

[0078] The perfluoropolyether compound of formula (II) is dissolved in methylethylketone forming a solution at 50% by weight. Said solution is additived to the commercial insecticidal formulation XYLAMON® (SOLVAY) obtaining a final concentration of compound (II) equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Hemlock wood specimen.

[0079] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 11, the hydro-repellence test values in Table 12, compared with those obtained with the not additived insecticidal formulation (first column) always applied in one single coat. TABLE 11 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 51 mm² 30.8 13.8 12.3 after 5 min. Drop area 61 mm² 32.6 14.1 12.3 after 10 min. Drop area 73.7 mm² 33.8 14.5 12.9 after 15 min. Drop area 84.8 mm² 35.1 15.3 13.5 after 20 min.

[0080] TABLE 12 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 22.2 mm² 7.9 7.8 7.6 Drop area H₂O/IPA 30/70 43.8 mm² 9.8 8.4 8.3 Drop area

EXAMPLE 7

[0081] To the commercial insecticidal formulation XYLAMON® (SOLVAY) the perfluoropolyether compound of formula (I) is additived at a concentration equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Parquet wood specimen.

[0082] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 13, the hydro-repellence test values in Table 14, compared with those obtained with the not additived insecticidal formulation (first column) always applied in one single coat. TABLE 13 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 200 mm² 65 38 34 after 5 min. Drop area 200 mm² 87 40 40 after 10 min. Drop area 200 mm² 90 49 43 after 15 min. Drop area 200 mm² 106  49 44 after 20 min.

[0083] TABLE 14 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 100 mm²  8  8  8 Drop area H₂O/IPA 30/70 100 mm² 18 14 13 Drop area

EXAMPLE 8

[0084] The perfluoropolyether compound of formula (II) is dissolved in methylethylketone forming a solution at 50% by weight. Said solution is additived to the commercial insecticidal formulation XYLAMON® (SOLVAY) obtaining a final concentration of compound (II) equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a Parquet wood specimen.

[0085] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 15, the hydro-repellence test values in Table 16, compared with those obtained with the not additived insecticidal formulation (first column) always applied in a single coat. TABLE 15 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 200 mm² 14 11 12 after 5 min. Drop area 200 mm² 14 12 13 after 10 min. Drop area 200 mm² 15 13 13 after 15 min. Drop area 200 mm² 15 13 13 after 20 min.

[0086] TABLE 16 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 100 mm²  8 7 7 Drop area H₂O/IPA 30/70 100 mm² 10 9 9 Drop area

EXAMPLE 9

[0087] To the commercial insecticidal formulation XYLAMON® (SOLVAY) the perfluoropolyether compound of formula (I) is additived at a concentration equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a pine wood specimen.

[0088] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 17, the hydro-repellence test values in Table 18, compared with those obtained with the not additived insecticidal formulation (first column) always applied in one single coat. TABLE 17 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 250 mm² 100 44 47 after 5 min. Drop area 250 mm² 121 56 64 after 10 min. Drop area 250 mm² 165 74 75 after 15 min. Drop area 250 mm² 181 79 84 after 20 min.

[0089] TABLE 18 Monofunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 100 mm² 10 10  9 Drop area H₂O/IPA 30/70 100 mm² 16 12 13 Drop area

EXAMPLE 10

[0090] The perf luoropolyether compound of formula (II) is dissolved in methylethylketone forming a solution at 50% by weight. Said solution is additived to the commercial insecticidal formulation XYLAMON® (SOLVAY) obtaining a final concentration of compound (II) equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a pine wood specimen.

[0091] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 19, the hydro-repellence test values in Table 20, compared with those obtained with the not additived insecticidal formulation (first column) always applied in one single coat. TABLE 19 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 250 mm² 14 14 13 after 5 min. Drop area 250 mm² 15 14 13 after 10 min. Drop area 250 mm² 15 14 14 after 15 min. Drop area 250 mm² 15 14 15 after 20 min.

[0092] TABLE 20 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 100 mm²  9  8  7 Drop area H₂O/IPA 30/70 100 mm² 10 10 10 Drop area

EXAMPLE 11

[0093] The perfluoropolyether compound of formula (II) is dissolved in methylethylketone forming a solution at 50% by weight. Said solution is additived to the commercial insecticidal formulation XYLOVALCERA® (VELECA) obtaining a final concentration of compound (II) equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a pine wood specimen.

[0094] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 21, the hydro-repellence test values in Table 22, compared with those obtained with the not additived insecticidal formulation (first column) always applied in one single coat. TABLE 21 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 55 mm² 12 11 11 after 5 min. Drop area 56 mm² 13 12 11 after 10 min. Drop area 58 mm² 14 12 12 after 15 min. Drop area 58 mm² 14 13 13 after 20 min.

[0095] TABLE 22 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 17 mm² 8 8 7 Drop area H₂O/IPA 30/70 34 mm² 9 9 8 Drop area

EXAMPLE 12

[0096] The perfluoropolyether compound of formula (II) is dissolved in methylethylketone forming a solution at 50% by weight. Said solution is additived to the commercial insecticidal formulation XYLOVALCERA® (VELECA) obtaining a final concentration of compound (II) equal to 1%, 5% and 10% by weight. The resulting product is applied by brushing to a parquet wood specimen.

[0097] The insecticidal formulation additived with the compound of the invention results effective in conferring hydro-/oil-repellence properties already with only one coat application. The oil-repellence test values are reported in Table 23, the hydro-repellence test values in Table 24, compared with those obtained with the not additived insecticidal formulation (first column) always applied in one single coat. TABLE 23 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. Drop area 51 mm² 16 14 12 after 5 min. Drop area 51 mm² 16 14 14 after 10 min. Drop area 54 mm² 17 15 14 after 15 min. Drop area 54 mm² 17 15 14 after 20 min.

[0098] TABLE 24 Bifunctional PFPE concentrations — 1% by wt. 5% by wt. 10% by wt. H₂O/IPA 60/40 17 mm²  8  8  8 Drop area H₂O/IPA 30/70 34 mm² 11 10 10 Drop area

EXAMPLE 13 (comparative)

[0099] The perfluopropolyether compound of structure (I) is not used as additive of a formulation for the wood treatment as in Examples 1-12, but used dispersed in a n-hexane solution containing the compound (I) at a concentration equal to 5% by weight.

[0100] 3 coats of product have been necessary to obtain a good coating of the surface of the hemlock wood specimen and to observe a conferring of hydro- and oil-repellence properties comparable to the case of Examples 1-12, in which only one coat application has been sufficient.

[0101] The oil-repellence test values are reported in Table 25, the hydro-repellence test values in Table 26, compared with the results of Examples 1, 3, 5 wherein the compound (I) is combined with various formulations for the wood treatment and applied in a single coat at the same concentrations. TABLE 25 Formu- Formu- With With lation lation With Anti- impreg- insecti- absence absence vegetative nant cidal 1 coat 3 coats 1 coat 1 coat 1 coat Drop area 72 mm² 20 37.9 36.2 37 after 5 min. Drop area 75 mm² 21.1 44.5 34.1 42.5 after 10 min. Drop area 78 mm² 21.2 48.8 60 52.7 after 15 min. Drop area 82 mm² 22.0 50.4 64 59 after 20 min.

[0102] TABLE 26 Formu- Formu- With With lation lation With Anti- impreg- insecti- absence absence vegetative nant cidal 1 coat 3 coats 1 coat 1 coat 1 coat H₂O/IPA 60/40 30 mm² 9.6 8 8.9 7.9 Drop area H₂O/IPA 30/70 33 mm² 12.2 15.4 13.6 16.3 Drop area

EXAMPLE 14 (comparative)

[0103] The perfluopropolyether compound of structure (II) is not used as additive of a formulation for the wood treatment as in Examples 1-12, but used dispersed in a n-hexane solution containing the compound (II) at a concentration equal to 5% by weight.

[0104] 3 coats of product have been necessary to obtain a good coating of the surface of the hemlock wood specimen and to observe a conferring of hydro- and oil-repellence properties comparable with the case of Examples 1-12, in which only one coat application has been sufficient.

[0105] The oil-repellence test values are reported in Table 27, the hydro-repellence test values in Table 28, compared with the results of Examples 2, 4, 6 wherein the compound (II) is combined with various formulations for the wood treatment and applied in one single coat at the same concentration. TABLE 27 Formu- Formu- With With lation lation With Anti- impreg- insecti- absence absence vegetative nant cidal 1 coat 3 coats 1 coat 1 coat 1 coat Drop area 41 mm² 11.4 13.6 15.8 13.8 after 5 min. Drop area 44 mm² 11.4 14 16 14.1 after 10 min. Drop area 46 mm² 12.4 14.4 16 14.5 after 15 min. Drop area 47 mm² 12.5 14.8 16.5 15.3 after 20 min.

[0106] TABLE 28 Formu- Formu- With With lation lation With Anti- impreg- insecti- absence absence vegetative nant cidal 1 coat 3 coats 1 coat 1 coat 1 coat H₂O/IPA 60/40 25 mm² 11 6.7 8.4 7.8 Drop area H₂O/IPA 30/70 30 mm² 8.4 8.1 11.3 8.4 Drop area

EXAMPLE 15 (comparative)

[0107] A monofunctional perfluoropolyether (PFPE) phosphate having the formula:

[Cl(CF₃F₆O)_(p)CF₂CH₂O(CH₂CH₂O)_(n)]_(m)P(O)_(m-3)

[0108] is used, with p═2−5, n═1−4, m═1−3 Said compound is used dispersed in a solution of isopropyl alcohol at a concentration equal to 5% by weight. Although up to 3 coats of product on a hemlock wood specimen have been applied, it has not been possible to obtain suitable hydro-repellence values as in the case of Examples 1-12, wherein only one coat application has been sufficient.

[0109] The hydro-repellence test values of the monofunctional phosphate are reported in Table 29 compared with the hydro-repellence values conferred by the compounds of structure (I) and (II) of the invention reported in Examples 1 and 2. TABLE 29 Compound (I) Compound (II) Phosphate Phosphate with Anti- with Anti- PFPE PFPE vegetative vegetative 1 coat 3 coats 1 coat 1 coat H₂O/IPA 60/40 100 mm² 100 8.0 6.7 Drop area H₂O/IPA 30/70 100 mm² 100 15.4 8.1 Drop area 

1. Use of mono- and bifunctional (per)fluoropolyether compounds as additives in formulations for the wood treatment, excluding the formulations based on paraffin waxes dissolved in hydrocarbon solvents, said perfluoropolyether compounds having the following structures: R_(f)—CFY—L—W(C) W—L—YFC—O—R_(f)—CFY—L—W(D) wherein: L is an organic group selected from —CH₂—(OCH₂CH₂)_(n)—, —CO—NR′—, with R′═H or C₁-C₄ alkyl group; n═0-8, preferably 1-3; Y═F, CF₃; W is selected from C₁-C₅₀ alkyl groups, preferably C₈-C₂₅, optionally containing one or more ether O, C₆-C₅₀ aryl groups, C₇-C₅₀ alkyl-aryl or aryl-alkyl groups; Rf has a number average molecular weight in the range 350-8,000, preferably 500-3,000 and it comprises repeating units having at least one of the following structures, statistically placed along the chain: (CFXO), (CF₂CF₂O), (CF₂CF₂CF₂O), (CF₂CF₂CF₂CF₂O), (CR₄R₅CF₂CF₂O), (CF(CF₃)CF₂O), (CF₂CF(CF₃)O), wherein X═F, CF₃; R₄ and R₅, equal to or different from each other, are selected from H, Cl, or perfluoroalkyl from 1 to 4 carbon atoms.
 2. Use according to claim 1 , wherein Rf is selected from the following structures: 1) —(CF₂O)_(a′)—(CF₂CF₂O)_(b′)—with a′/b′ in the range 0.5-2, extremes included, a′ and b′ being integers such as to give the above mentioned molecular weight; 2) (C₃F₆O)_(r)—(C₂F₄O)_(b)—(CFXO)_(t)—with r/b═0.5-2.0; (r+b)/t is in the range 10-30, b, r and t being integers such as to give the above mentioned molecular weight, X has the above mentioned meaning; 3) —(C₃F₆O)_(r′)—(CFXO)_(t′)—when t′ is different from O then r′/t′═10-30, r′, and t′ being integers such as to give the above mentioned molecular weight; x has the above indicated meaning; 4) —(OCF₂CF(CF₃) )_(z)—OCF₂(R′f)_(y)—CF₂O—(CF(CF₃)CF₂O)_(z)—wherein z is an integer such that the molecular weight is the above mentioned one; y is an integer between 0 and 1 and R′f is a fluoro-alkylene group having for example 1-4 carbon atoms; 5) —(OCF₂CF₂CR₄R₅)_(q)—OCF₂(R′f)_(y)—CF₂O—(CR₄R₅CF₂CF₂O)_(s)— wherein: q and s are integers such that the molecular weight is the above mentioned one; R₄, R₅, R′f, y have the above mentioned meaning; 6) —(C₃F₆O)_(r′″)(CFXO)_(t′″)—OCF₂(R′f)_(y)—CF₂O(CF(CF₃)CF₂O)_(r′″)(C—FXO)_(t′″)— wherein r′″/t′″═10-30, r′″ and t′″ being integers such as to give the above mentioned molecular weight;
 3. Use according to claims 1-2, wherein in the structure (C) the other end group is of the T—O— type, wherein T is a (per) fluoroalkyl group selected from: —CF₃, —C₂F₅, —C₃F₇, —CF₂Cl, —C₂F₄Cl, —C₃F₆Cl; optionally one or two F atoms, preferably one, being replaced by H.
 4. Use according to claims 1-3, wherein the perfluoropolyether compounds have structure (D) wherein L is —CO—NR′—, with R′═H; W is a C₈-C₂₅ alkyl group; Rf has structure 1).
 5. Use according to claims 1-4, wherein the formulations for the wood treatment are selected from the impregnating, antivegetative, insecticidal, anti-mould formulations, paints, preferably based on solvents, such as ketones, alcohols, glycols, hydrocarbons.
 6. Use according to claim 5 , wherein the impregnating formulations comprise as main components natural oils, acrylic and polyurethane polymers.
 7. Use according to claim 5 , wherein the anti-vegetative formulations comprise as main components limonene, alkyd resins and fluorinated acrylic polymers.
 8. Use according to claim 5 , wherein the insecticidal formulations comprise as main components dichlofluoanid, pernethrin, linseed oil and dibutylphthalate.
 9. Use according to claims 1-8, wherein the compounds are added to the formulations in concentrations in the range 0.01-10% by weight, preferably 0.1-5% by weight with respect to the formulation weight.
 10. Use according to claims 1-9, wherein the formulation is applied by brushing, spraying. 